Magnetic snap action electric switches



y 1969 DHU AINE J. DAVIS 3,458,841

I MAGNETIC SNAP ACTION ELECTRIC SWITCHES Filed March 7, 1967 2 Sheets-Sheet 1 3 55 36 34 25 I 1' Y J z, 1 I "a" 23. Z2 53 f 34 INVENTOR. fl/lc/flnve' J. 54145 ATTORNEY J ly 1969 DHU AINE J. DAVIS MAGNETIC SNAP AC'I'lON ELECTRIC SWITCHES 2 Sheets-Sheet 2 Filed March 7. 1967 INVENTOR fif/b4/NE 04145 A TTORNE Y United States Patent 01 ice 3,458,841 Patented July 29, 1969 3,458,841 MAGNETIC SNAP ACTION ELECTRIC- SWITCHES Dhn Aine J. Davis, Wheaten, 111., assignor to Hermetic Coil Co., Inc, Wheaten, 11]., a corporation of Connecticut Filed Mar. 7, 1967, Ser. No. 621,171 Int. Cl. H0111 9/54 U.S. Cl. 335207 16 Claims ABSTRACT OF THE DISCLOSURE Magnetic switches for alternatively opening and closing an electrical circuit by means of coaxially disposed magnetic elements whose respective polarities are arranged to exert magnetic repulsion forces for obtaining snap action operation.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to magnetic switches and, more particularly, to improved magnetic means and mechanisms for operating said switches.

Description of the prior art Examples of the prior art are disclosed in the following patents: United States-Nos. 2,520,935, 2,521,723, 2,548,581, 2,814,687, 2,847,528, 2,848,572, 2,853,576, 2,877,361, 2,896,043, 2,915,681, 2,945,928, 2,999,915, 3,012,116, 3,025,372, 3,055,999, 3,114,809, 3,115,563, 3,125,651, 3,151,226, 3,165,605, 3,167,624, 3,167,694, 3,170,999, 3,171,003, 3,171,913, 3,175,060, 3,176,097, 3,209,097, British 903,170, British 906,521.

The foregoing patents disclose various types of electromagnetic devices that are used for switching purposes. It is considered that these prior art devices do not produce the snap action operation achieved by applicants invention herein and do not lend themselves as readily to incorporation into hermetically sealed switches that can be operated as simply as applicants.

SUMMARY OF THE INVENTION In many types of electrical circuitry, it is desirable to provide switch devices which are hermetically sealed against humid or liquid environments or against the danger of explosion of combustible gases or the like surrounding the electrical circuitry. In those circumstances, it is also desirable to provide actuating controls located externally of the hermetically sealed chamber which are manually operable to open and close the electrical circuits with certainty that the switching or circuit closing element will be firmly urged into either the contacting or non-contacting positions.

In order to achieve the foregoing objectives, the present invention consists of a magnetically operated switch system which comprises a pair of coaxially movable magnetic elements whose polarities are arranged to exert magnetic repulsion forces upon each other when either of said elements is moved in one direction, thereby causing the other of said elements to move in the opposite direction into either an open circuit or closed circuit position. In most of the embodiments of the present invention, the outer coaxial element is usually in the form of a ring magnet while the inner coaxial element may be formed either as a ring or as a solid rod magnetic element. When the inner switching magnetic element, together with the electrical terminals are enclosed in a hermetically sealed chamber, the manipulation of the outer actuator magnetic ring longitudinally in respect of the inner magnetic ele- 3,222,474, Canadian 640,263, British 892,579,.

ment will cause the latter to move in a respective opposite longitudinal direction to open or close the electrical circuit, as desired.

By arranging for the movement of the respective mag netic elements to take place by magnetic repulsion forces, the switching magnet is continually urged against the contact elements to ensure the integrity of the closed electrical circuit. The movement of the actuator magnet in either longitudinal direction will cause the switching magnet to move by snap action in the opposite longitudinal direction Without fail and with the assurance that the switching magnet will be continually urged by the magnetic repulsion forces to maintain itself in either of the desired circuit closing or circuit opening positions.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a generalized fragmentary view of an electrical line cord assembly, partly broken away, showing the magnetic switch of the present invention and a plug attached to said line cord for connection to an electric socket.

FIGURE 2 is a greatly enlarged vertical section view of the magnetic switch with the switching elements in an open circuit condition, some parts being shown in elevation;

FIGURE 3 is similiar to FIGURE 2 showing the switching elements in a closed circuit condition;

FIGURE 4 is a section view taken on line 4-4 of FIGURE 2;

FIGURE 5 is a section view taken on line 55 of FIGURE 2;

FIGURE 6 is another embodiment of the present invention showing a magnetic switch in central vertical section, connected to a light bulb circuit, some parts being shown in elevation, and some parts being shown schematically;

FIGURE 7 is a central vertical section view of a still further embodiment of the present invention, some parts being shown in elevation; and

FIGURE 8 is a central vertical section view of another embodiment of the present invention incorporating a neon bulb in the controlled electrical circuit, some parts being shown in elevation and an electrical circuit connected to said switch and illustrated schematically.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGURES 1 through 5, one of the embodiments of the present invention comprises a switching assembly incorporated into an electrical line cord, generally designated 21, having two parallel lead lines 22 and 23 which are connected to plug 24 for insertion into a suitable socket to which a power line is connected.

The switch assembly, generally designated 26, may be mounted on line cord 21 by means of molding a pair of spaced apart end caps 27 and 28 thereon, said caps being made of a suitable material such as vinyl or the like and which, preferably, may be made of the same material as the insulation coating lead lines 22 and 23. End caps 27 and 28 may be molded onto line cord 21 after the other components of the magnetic switch have been assembled therein.

Lead line 22 extends uninterruptedly through and between caps 27 and 28. In the area between caps 27 and 28, a section of lead line 23 is cut away and removed, the respective cut ends being stripped .of a short length of insulation to expose the bare wire conductors 23A and 23B.

An elongated conductor tube 29 made of brass or other suitable electrically conductive material is mounted c0- axially around lead line 22 extending from the region of cap 27 to cap 28. Mounted coaxially around tube 29 is a tubular spacer body 31 made of insulating material such as nylon or the like, said body having an integrally formed inwardly extending annular collar 32 whose inner surface fits closely with a portion of conductor tube 29.

The right end of conductor ring 29 terminates in an integrally formed outwardly extending annular flange 33 which is spaced apart from the right surface of collar 32 to accommodate therebetween a ring terminal 34 made of electrically conductive material such as brass or the like. Terminal 34 has an integrally formed perpendicular extension 36 extending rearwardly and terminating in an integrally formed leaf 37 which is crimped around the exposed end of wire conductor 23A to establish electrical connection therewith.

Coaxially mounted around and near the left end of conductor tube 29 is a circular spacer plug 38 made of insulating material such as nylon or the like, said plug having a pair of longitudinal recesses 41 and 42 spaced 180 apart from each other. Recesses 41 and 42 accommodate terminal elements 43 and 44, respectively, made of electrically conductive material such as brass or the like. Terminal elements 43 and 44 each have integrally formed fingers 46 and 47, respectively, extending inwardly over the right surface of plug 38.

Terminals 43 and 44 each have forwardly extending integrally formed L-shaped extensions 48 and 49, respectively. Terminal extension 48 has an integrally formed leaf 51 which is crimped around the exposed end of wire conductor 2313 to form electrical connection therewith.

Soldered or otherwise electrically connected to terminal extension 49 is one leg portion of an electrically conductive U-shaped jumper 52, made of brass or the like, the other leg portion of which is soldered or otherwise electrically connected to an end portion of conductor tube 29 to establish electrical connection therebetween.

Freely movable reciprocably along and mounted coaxially around conductor tube 29 is the elongated trunk of an electrically conductive tubular eyelet 53, made of brass or the like, the ends of said eyelet terminating in integrally formed outwardly extending annular flanges 54 and 56, respectively. Mounted fast on eyelet 53 and secured between flanges 54 and 56 is a circular inner ring magnet 57 made of a suitable permanent magnetic material such an Alnico, ceramic composition, or the like.

The assembly of all of the parts described hereinbefore as located between end caps 27 and 28 are hermetically encapsulated by means of a tubular sheath or sleeve 58 of a suitable insulating material, such as vinyl or the like, said sleeve being fairly stiff and resistant to bending or flexing.

End caps 27 and 28 which are hermetically molded around lead lines 22 and 23 are also hermetically molded around the respective ends of sleeve 58 to form a liquidand air-tight enclosure for all of the parts described hereinbefore.

End caps 27 and 28 each have integrally formed outwardly extending annular flanges 61 and 62, respectively, between which is located a circular outer ring magnet 63 made of suitable permanent magnetic material such as Alnico, ceramic composition, or the like. Outer ring magnet 63 which encircles sleeve 58 is arrayed coaxially relative to inner ring magnet 57. Outer ring magnet 63 is freely movable reciprocably and coaxially over sleeve 58 between the limits of the opposing inner walls of flanges 61 and 62.

The respective polarities of inner and outer ring magnets 57 and 63 are arranged in the same relative directions as indicated by the N and S markings in FIGURES 2 and 3. 'In the open circuit condition of switch 26 as illustrated in FIGURE 2, when outer ring magnet 63 abuts flange 61, inner ring magnet 57 is automatically urged to the right whereby flange 54 is caused to abut collar 32 as a result of the magnetic repelling forces exerted between said respective magnets. In this circum- 4 stance, an open circuit condition obtains between the spaced apart ends 23A and 23B of lead line 23.

When outer magnet 63 is moved to the right to abut flange 62, inner magnet 57 is automatically urged by snap action to the left, as shown in FIGURE 3, whereby flange 56 is caused to abut fingers 46 and 47 of respective terminals 43 and 44 simultaneously. In this circumstance, the electrical circuit is closed between ends 23A and 23B of lead line 23 by Way of extension 36, ring terminal 34, flange 33, conductor tube 29, jumper 52, extension 49, terminal 44, finger 47, flange 56 of eyelet 53, finger 46, terminal 43, and extension 48. Thus, electric current is conducted between and through both segments of lead line 23 thereby closing the circuit to the apparatus to which the line cord switch assembly is connected.

The longitudinal movement of the outer ring actuator magnet 63 causes the snap action longitudinal movement of the inner switching magnet 57 by virtue of the mutually repelling magnetic forces existing between them as a result of the polar alignment of said respective magnets in the same direction. Accordingly, in either of the two respective positions of magnets 57 and 63 in FIGURES 2 and 3, the inner magnet 57 is urged into its open circuit or closed circuit location by the magnetic repulsion forces radiating from the respective N poles and the respective S poles of the two magnets. Because of the coaxial alignment of the respective magnets 63 and 57, these magnetic repulsion forces that obtain between the similar poles of the respective magnets are considerably greater than any lateral magnetic attraction forces that may be exerted between the opposite poles of said respective magnets. Accordingly, the longitudinal movement of the actuating magnet 63 ensures the snap action longitudinal movement of the switching magnet 57 by snap action in the opposite direction into either the open circuit or closed circuit positions.

In both open circuit and closed circuit conditions of switch 26, outer ring magnet 63 is under magnetic repulsive forces operative between itself and inner ring magnet 57 normally to remain in the location in which it has been placed. When outer magnet 63 is moved from either the open or closed circuit location to the other, a modicum of magnetic resistance is encountered until outer magnet 63 passes a point relative to inner magnet 57 where the magnetic repulsion forces change to the opposite direction, at which time inner magnet 57 is caused to move in the opposite direction by snap action from one circuit location to the other circuit location, thereby quickly making or breaking the circuit, as desired. The relatively fast action achieved by use of magnetic repulsion forces makes the switch ideal as a precision snap switch for both AC. and D.C. use.

The present invention is advantageous in overcoming what is known as contact bounce encountered in previous switches in which the movable contact, when actuated, tends to vibrate and to repeat several make and break movements before coming to rest and making a steady sustained electrical connection. As a result of the repulsion action of the magnetic elements of the present invention, however, such vibration or contact bounce is completely eliminated or reduced to minimum.

When inner ring magnet 57 is thrust to the left, as in FIGURE 3, magnetic repulsion continues to exert its force even after flange 56 has made contact with fingers 46 and 47, thereby preventing magnet 57 from moving to the right. Thus, intimate contact is sustained between flange 56 and fingers 46 and 47 to ensure the integrity of the closed electrical circuit. As shown in the embodiment of FIGURES 2 and 3, fingers 46 and 47 may be bent rearwardly so that a nesting action takes place when flange 56 comes into contact therewith to further reduce the possibility of contact bounce or vibration.

Also, by virtue of the magnetic repulsion forces de scribed hereinbefore, outer ring magnet 63 is caused normally to remain automatically in the open circuit or closed circuit position to which it has last been moved. Outer ring magnet 63 may be manipulated by hand or by any other suitable electrical or mechanical means for moving it into the open circuit or closed circuit locations. As outer magnet 63 is moved from a previously disposed location, magnetic resistance is encountered as like poles of both inner magnet 57 and outer magnet 63 approach each other until a maximum point of repulsion is achieved beyond which said repulsive forces act to cause inner magnet 57 to move by snap action in the opposite direction.

Another embodiment of the invention is shown in FIG- URE 6 where the magnetic switch is operable as a remote unit which can be connected into any circuit for an electrically actuated apparatus such as an electric motor or, for example, an incandescent bulb 71 connected by way of a first lead line 72 to plug 73 which is insertable into a socket leading to a suitable electric power source. A second lead line 74 between bulb 71 and socket 73 is interrupted by a series connected magnetic switch, generally designated 76. Lead line 74 is connected to a pair of terminals 77 and 78 which extend through the base 79 of switch 76 and terminate in a pair of spaced apart electrical contacts 81 and 82, respectively. Switch 76 comprises a tubular housing 83 made of suitable insulating material such as nylon, Bakelite, or the like, and which may be bonded by a liquidand air-tight seal with base 79 which is also made of a suitable insulating material. The upper end of housing 83 is enclosed by a cap 84 forming an airand liquid-tight seal 'with housing 83 and also being made of a suitable insulating material. Base 79 and cap 84 have annular flanges 86 and 87, respectively, which extend outwardly beyond the perimeter of housing 83.

Within the hermetically sealed chamber defined by housing 83, base 79, and cap 87, is located an inner ring magnet 89 made of a suitable permanent magnetic material such as Alnico, ceramic composition, or the like, said inner magnet being freely movable longitudinally and reciprocably between both ends of said chamber. The axial aperture of magnet 89 contains an electrically conductive eyelet 91 made of brass or the like, which terminates at its lower end in a downwardly and outwardly extending annular flange 92.

When inner magnet 89 rests at the bottom of switch 76 as shown in FIGURE 6, flange 92 is in contact with contact elements 81 and 82, thereby closing the electrical circuit therebetween and concomitantly closing the electrical circuit in line conductor 74.

Located around the perimeter of housing 83 is an outer ring magnet 93 made of suitable permanent magnetic material such as Alnico, ceramic composition, or the like, said outer ring magnet 93 being reciprocably movable longitudinally and axially in respect of housing 83 and inner magnet 89. Outer ring magnet 93 is movable Within the limits defined by the opposing parallel surfaces of flanges 86 and 87, respectively.

In the illustration of FIGURE 6, when outer ring magnet 93 abuts flange 87, the repelling magnetic forces that are operative between said magnet and inner magnet 89 cause the latter to be urged against contacts 81 and 82 to close the electrical circuit therebetween. When outer ring magnet 93 is caused to abut flange 86, inner magnet 89 is caused by said magnetic repulsion forces to move upwardly into a position of abutmentagainst cap 84 thereby opening the electrical circuit between contacts 81 and 82.

It will be evident that the embodiment of the invention shown in FIGURE 6 is useful as a hermetically sealed switch that may be located in a remote position from the apparatus to be controlled. Thus, the switch may be freely operated in explosive, corrosive, or other atmospheric conditions with safety and without endangering operating and attendant personnel.

Those portions of contacts 81 and 82 that extend into the interior of housing 83 are bent outwardly and form oblique or curved mating surfaces for accommodation with the oblique or curved surfaces of flange 92. By this 6 means, contact bounce is completely eliminated or greatly diminished.

A further embodiment of the invention is shown in FIGURE 7 wherein the switch, generally designated 95, comprises a circular housing 96 enclosed on the bottom by floor 97 and on top by collar 98, said housing, bottom and collar being formed of a suitable insulating material such as nylon, Bakelite, or the like. In a manner similar to the embodiment of FIGURE 6, switch of FIGURE 7 is intended to be connected in series in one conductor of a double wire line cord or the like, said conductor being connected to a pair of terminals 101 and 102 which termimate in respective spaced apart contact elements 103 and 104 extending into the interior of housing 96.

Located within housing 96 and reciprocably movable longitudinally and axially therein is a ring magnet 106 made of a suitable permanent magnetic material such as Alnico, ceramic composition, or the like. The interior axial wall of magnet 106 is lined with an electrically conductive eyelet 107 made of brass or the like, the bottom of said eyelet terminating in an integrally formed flange 108 extending downwardly and outwardly, relative to the bottom surface of magnet 106. When magnet 106 is at rest at the bottom of housing 96, flange 108 establishes electrical connection between contacts 103 and 104.

Collar 98 has a central aperture 109 which movably accommodates reciprocable shaft 111 of a switch actuator, said shaft terminating at its top in a button 112 which may be moved manually or otherwise axially relative to housing 96. Shaft 111 has a longitudinal slot 113 which accommodates one portion of a pin 114, the other portion of which is mounted in collar 98. Pin 114 limits the motion of shaft 111 so that the latter will not be accidentally removed from housing 96.

Connected to the bottom end of shaft 111 is a permanent magnet 116 having a circular diameter, said magnet being made of a suitable permanent magnet material such as Alnico, ceramic composition, or the like. Magnet 116 is movable freely longitudinally through and within the axial interior of ring magnet 106. When button 112 and shaft 111 are in the position as shown in FIGURE 7, the magnetic repulsion forces operative between magnet 116 and magnet 106 cause the latter to be urged against contacts 103 and 104 to close the electrical circuit therebetween. Also, in this position, button 112 and shaft 111 are sustained in their locations by the same magnetic repulsion forces. When pressure is applied downwardly upon button 112 and shaft 111 against said repulsion forces to the bottom limit of motion of magnet 116, the magnetic repulsion forces between the two magnets become operative in the opposite direction thereby causing ring magnet 106 to move upwardly into a position abutting collar 98, thereby opening the electrical circuit between contacts 103 and 104.

A still further embodiment of the invention is shown in FIGURE 8 wherein the magnetic switch of the present invention is combined in a single housing with an automatically operating electric light. The combination electric switch and light device comprises a cylindrical housing 121 made of suitable insulating material such as nylon, Bakelite, or the like, and having connected thereto a floor 122 made of a similar insulating material, said floor having an annular, integrally formed flange 123 extending outwardly from the perimeter of housing 121. Connected to the top of housing 121 is a truncated conical cap 124 made of a suitable insulating material or the like, said cap being at least partially translucent or transparent. Cap 124 has an annular flange 125 extending outwardly from the perimeter of housing 121.

Mounted in a central aperture in floor 122 is the base 126 of an electric bulb 127, said bulb extending axially into the interior of housing 121. Bulb 127 may comprise either the incandescent or neon type, as desired or required.

Also extending through suitable apertures in floor 122 is a pair of terminals 128 and 129 which terminate in a pair of spaced apart electrical contacts 131 and 132, respectively, extending partially into the interior of housing 121.

Located within housing 121 is an inner ring magnet 133 made of a suitable permanent magnetic material such a Alnico, ceramic composition, and the like. Lining the interior axial aperture of magnet 133 is an electrically conductive eyelet 134 made of brass or the like, the bottom of said eyelet having an integrally formed annular flange 135 extending downwardly and outwardly along a portion of the bottom of magnet 133. Magnet 133 is freely reciprocably movable longitudinally and axially in respect of bulb 127 and of housing 121. When magnet 133 is in the location shown in FIGURE 8, flange 135 establishes electrical connection between contacts 131 and 132.

Located around the perimeter of housing 121 is an outer ring magnet 136 made of a suitable permanent magnetic material such as Alnico, ceramic composition, or the like, said outer magnet 136 being reciprocably movable axially and longitudinally in respect of housing 121 and inner magnet 133.

As shown in FIGURE 8, when inner magnet 133 is in its lower position, outer magnet 136 is sustained in its upper position against flange 125 by means of magnetic repulsion forces operating therebetween. When outer magnet 136 is manually or otherwise depressed to a lower position against flange 123, inner magnet 13 3 is automatically raised by the operation of the magnetic repulsion forces acting therebetween to cause the flange 135 to become spaced apart from contacts 131 and 132, thereby opening the electrical circuit therebetween.

Connected to terminal 128 is one end of lead line L1, the other end of which is connected to a suitable electric power source. Another parallel lead line L2 from said source is connected to base 126 of bulb 127. Connected to terminal 129 is one end of lead line P1, the other end of which is connected to a load such as an electric motor or other electrical system or apparatus to be controlled by the magnetic switch. Connected between the load and line L2 is a return line P2. If indicator bulb 127 is a gas discharge or neon light, then a suitable resistor R is connected between base 126 and terminal 129.

When inner magnet 133 is in the location as shown in FIGURE 8, the electrical circuit is closed whereby the load is actuated and indicator bulb 127 is lit, the light from said bulb being visible through cap 124. When outer magnet 136 is moved downward to a location abutting flange 123, inner magnet 133 is raised automatically by magnetic repulsion forces to a position abutting the inner surface of cap 124 thereby opening the circuit between contacts 131 and 132, in which circumstance bulb 127 is extinguished and the load is deenergized.

In all of the embodiments of FIGURES 6, 7 and 8, it is understood that the magnetic polar alignments are the same as in FIGURES 2 and 3 whereby the longitudinal movement of the actuating magnet causes the longitudinal movement of the switching magnet in the opposite direction by operation of magnetic repulsion forces, as described hereinbefore. It -will be noted that in all of the embodiments of the invention herein, the outer magnet is always circular while the inner magnet may be either in the form of a ring or in the form of a rod.

As is evident in the embodiment of FIGURE 7, the actuating magnet may be a solid magnetic rod as an inner element, while the switch magnet is in the form of a coaxial ring. In FIGURE 7, suitable sealing means may be provided between shaft 111 of actuator magnet 116 and aperture 109 of end wall 98 in order to provide hermetic sealing for the electrical elements within housing 96.

It is understood that in all of the embodiments of the present invention, the inner and outer magnetic elements are in suitable radial and axial proximity to each other and their longitudinal dimensions are selected and determined so that the mutual repulsion magnetic forces are operative to efiect the switching actions described herein. Also, the axial limits of travel of both magnetic elements will be determined by the dimensions of the housing within which the inner magnet moves, by the spaced apart flanges located externally of the housing for limiting the travel of the outer magnetic element, and by other suitable means when both magnetic elements are within the housing as in FIGURE 7, for example.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described, for obvious modifications -will occur to those skilled in the art.

What is claimed is:

1. An electric switch comprising a line cord, first and second insulated conductor wires in said cord, a switch housing mounted on side line cord, said first conductor wire extending axially through said housing, said second conductor wire being segmented whereby two ends of said second wire extend into said housing and are spaced apart from each other therein, a conductor tube coaxially mounted over said first conductor wire within said housing, one end of said second conductor wire being connected to one end of said conductor tube, a first terminal connected to the other end of said conductor tube, a second terminal connected to the other internal end of said second conductor wire, a first ring magnet positioned coaxially around said conductor tube and movable longitudinally and reciprocably thereover, a conductor element mounted on said first ring magnet, said first ring magnet being movable alternately into an open circuit position and a closed circuit position, said conductive element on said first ring magnet establishing electrical connection between said first and second terminals when said first ring magnet is only in the closed circuit position, and a second ring magnet coaxially mounted around said housing and movable reciprocably and longitudinally thereover, the movement of said second ring magnet in either direction causing the movement of said first ring magnet in the opposite direction.

2. A mechanism according to claim 1 wherein the northsouth polarities of both first and second ring magnets are axially arrayed in the same direction.

3. A mechanism according to claim 1 wherein said housing is hermetically sealed on said line cord to exclude the atmosphere from the ends of said second conductor wire in the interior of said housing, said conductor tube, said first and second terminals, said conductor element and said first ring magnet.

4. A mechanism according to claim 1 wherein the movement of said second ring magnet in either direction causes the movement of the first ring magnet in the 0pposite direction by means of magnetic repulsion forces exerted between said ring magnets.

5. A mechanism according to claim 1 and further comprising a pair of spaced apart flanges on the exterior of said housing, said flanges limiting the axial movement of said second ring magnet in either direction.

6. A mechanism according to claim 5 wherein said first and second ring magnets are in suitable radial and axial proximity to each other and the longitudinal movements of both said ring magnets are limits in respect of each other whereby the movement of the second ring magnet from one limit to the other in one direction causes the movement of the first ring magnet from one limit to the other in the opposite direction.

7. A switch mechanism comprising a housing, a pair of spaced apart electrodes located in the interior of said housing at one thereof, a first ring magnet movable reciprocably and coaxially in the interior of said housing, a second ring magnet located around the exterior of said housing and movable reciprocably and coaxially in respect thereof and in respect of said first ring magnet, a light bulb positioned within said housing, said first ring magnet encircling said light bulb and being movable freely in respect thereof, the magnetic polarities of said first and second ring magnets being arrayed in respect of each other whereby the movement of said second ring magnet in either axial direction causes the movement of the first ring magnet in the opposite direction by magnetic repulsion forces exerted between said ring magnets, and an electrical conductor mounted on said first ring magnet, said conductor closing the circuit between said electrodes when said first ring magnet is urged by magnetic repulsion forces toward and against said electrodes, said conductor being spaced apart from said electrodes to open the circuit therebetween when said first ring magnet is displaced therefrom by the movement of said second ring magnet in the opposite direction, and electrical circuitry connecting said electric bulb with said electrodes whereby the closing of the circuit between said electrodes by said conductor simultaneously causes the illumination of said light bulb and whereby the opening of the circuit between said electrodes causes the extinguishment of said bulb.

8. A switch mechanism according to claim 7 wherein the north-south polarities of both first and second ring magnets are axially arrayed in the same direction.

9. A switch mechanism according to claim 7 wherein said housing is hermetically sealed and the components of said mechanism contained within said housing are protected from the external atmosphere.

10. A switch mechanism according to claim 7 wherein at least one end of said housing is made of a selected material through which illumination from said light bulb is visible.

11. An electric switch comprising a tubular housing, an electrical element mounted axially within said housing, a first ring magnet in the interior of said housing and encircling said electrical element coaxially and movable longtudinally in respect thereof, a pair of spaced contact terminals in the interior of said housing, one of said terminals being connected to said electrical element, an electrically conductive element on said first ring magnet, said conductive element being adapted to close the circuit between said contact terminals to energize said electrical element, and a second ring magnet located externally and coaxially of said housing and movable longitudinally in respect thereof, the movement of said second ring magnet in either direction causing the movement of said first ring magnet in the opposite direction for alternately closing and opening the circuit between said terminals.

12. A switch according to claim 11 wherein said electrical element comprises an elongated electrically conductive line conductor.

13. A switch according to claim 11 wherein said electrical element comprises an electric illuminating bulb.

14. An electric switch comprising a line cord, first and second insulated conductor wires in said cord, a first ring magnet located coaxially around and movable longi tudinally in respect of said first wire, said second wire being interrupted intermediate its ends by means of a pair of spaced apart terminals, an electrically conductive element on said first ring magnet, said first ring magnet being movable alternately between an open circuit position and a closed circuit position whereby in the latter position said conductive element closes the circuit between said terminals of said second wire, and a second ring magnet mounted coaxially in respect of said first ring magnet and movable longitudinally in respect of said first wire, the movement of said second ring magnet in either direction causing the movement of said first ring magnet in the opposite direction for alternately closing and opening the circuit between said terminals.

15. A switch according to claim 14 and further comprising an insulating housing surrounding said first and second wires, said terminals, and said first ring magnet, and wherein said second ring magnet is located on the exterior of said housing and movable relative thereto.

16. An electric switch comprising a line cord, first and second conductor wires in said cord, a first ring magnet encircling said first wire and movable longitudinally relative thereto, a pair of spaced apart electric terminals interrupting said second wire, an electrically conductive element on said first ring magnet adapted to close the circuit between said pair of terminals, and a second ring magnet located coaxially relative to said first magnet and movable longitudinally in respect of said first wire to muse said first magnet to move alternately into either a i cuit closing or a circuit opening position relative to said terminals.

References Cited UNITED STATES PATENTS 3,273,091 9/1966 Wales 335-207 3,274,369 9/1966 Quinn.

3,376,527 4/1968 Risk 335-207 FOREIGN PATENTS 1,141,000 12/ 1962 Germany.

BERNARD A. GILHEANY, Primary Examiner R. N. ENVALL, JR., Assistant Examiner US. Cl. X.R. 200-167, 168; 33517 

